1. Field of the Invention
The present invention relates to an indicator for use in vehicles having an energy storage device. The indicator indicates an amount of power available from the energy storage device.
2. Background Art
A hybrid electric vehicle (HEV) includes at least a primary power source and a secondary power source. Typically, the primary power source is a fuel cell, an engine, or other energy generating device, and the secondary power source is a battery or other energy storing device.
The secondary power source, such as the battery, can be used to provide energy to an electric motor or other electric device for electric assist. The electric assist generally includes providing torque for driving the vehicle. The electric assist torque can supplement torque provided by the primary power source, it can be the sole source of torque, or it can used to engage an electric four-wheel drive system.
The secondary power source stores energy as opposed to generating energy. As such, the amount of energy the secondary power source can provide for generating torque is limited to its stored energy.
It is desirable to indicate to the driver the amount of stored energy available from the secondary power source. As such, there exists a need to indicate an amount of power available from the energy storage device.